Add UI Button element

Adafruit_GFX.cpp

@@ -518,3 +518,70 @@ void Adafruit_GFX::invertDisplay(boolean i) {
   // Do nothing, must be subclassed if supported
 }
 
+/***************************************************************************/
+// code for the GFX button UI element
+
+Adafruit_GFX_Button::Adafruit_GFX_Button(void) {
+   _gfx = 0;
+}
+
+void Adafruit_GFX_Button::initButton(Adafruit_GFX *gfx,
+					  int16_t x, int16_t y, 
+					  uint8_t w, uint8_t h, 
+					  uint16_t outline, uint16_t fill, 
+					  uint16_t textcolor,
+					  char *label, uint8_t textsize)
+{
+  _x = x;
+  _y = y;
+  _w = w;
+  _h = h;
+  _outlinecolor = outline;
+  _fillcolor = fill;
+  _textcolor = textcolor;
+  _textsize = textsize;
+  _gfx = gfx;
+  strncpy(_label, label, 9);
+  _label[9] = 0;
+}
+
+ 
+
+ void Adafruit_GFX_Button::drawButton(boolean inverted) {
+   uint16_t fill, outline, text;
+
+   if (! inverted) {
+     fill = _fillcolor;
+     outline = _outlinecolor;
+     text = _textcolor;
+   } else {
+     fill =  _textcolor;
+     outline = _outlinecolor;
+     text = _fillcolor;
+   }
+
+   _gfx->fillRoundRect(_x - (_w/2), _y - (_h/2), _w, _h, min(_w,_h)/4, fill);
+   _gfx->drawRoundRect(_x - (_w/2), _y - (_h/2), _w, _h, min(_w,_h)/4, outline);
+   
+   
+   _gfx->setCursor(_x - strlen(_label)*3*_textsize, _y-4*_textsize);
+   _gfx->setTextColor(text);
+   _gfx->setTextSize(_textsize);
+   _gfx->print(_label);
+ }
+
+boolean Adafruit_GFX_Button::contains(int16_t x, int16_t y) {
+   if ((x < (_x - _w/2)) || (x > (_x + _w/2))) return false;
+   if ((y < (_y - _h)) || (y > (_y + _h/2))) return false;
+   return true;
+ }
+
+
+ void Adafruit_GFX_Button::press(boolean p) {
+   laststate = currstate;
+   currstate = p;
+ }
+ 
+ boolean Adafruit_GFX_Button::isPressed() { return currstate; }
+ boolean Adafruit_GFX_Button::justPressed() { return (currstate && !laststate); }
+ boolean Adafruit_GFX_Button::justReleased() { return (!currstate && laststate); }

Adafruit_GFX.h

@@ -87,4 +87,31 @@ class Adafruit_GFX : public Print {
     wrap; // If set, 'wrap' text at right edge of display
 };
 
+class Adafruit_GFX_Button {
+
+ public:
+  Adafruit_GFX_Button(void);
+  void initButton(Adafruit_GFX *gfx, int16_t x, int16_t y, 
+		      uint8_t w, uint8_t h, 
+		      uint16_t outline, uint16_t fill, uint16_t textcolor,
+		      char *label, uint8_t textsize);
+  void drawButton(boolean inverted = false);
+  boolean contains(int16_t x, int16_t y);
+
+  void press(boolean p);
+  boolean isPressed();
+  boolean justPressed();
+  boolean justReleased();
+
+ private:
+  Adafruit_GFX *_gfx;
+  int16_t _x, _y;
+  uint16_t _w, _h;
+  uint8_t _textsize;
+  uint16_t _outlinecolor, _fillcolor, _textcolor;
+  char _label[10];
+
+  boolean currstate, laststate;
+};
+
 #endif // _ADAFRUIT_GFX_H